A centrifugal compressor is used for compressing fluid, and it mainly comprises an impeller, a shaft, a cylinder, a diffuser, corners, a reflux, an intake manifold and an exhaust pipe. An inlet guide vane device is employed on the impeller.
When the centrifugal compressor operates, the impeller rotates in a high speed so that the airflow inside thereof rotates accordingly. By the impact of the centrifugal force generated by the rotation of the impeller, the fluid is driven to the diffuser behind. Thus, a vacuum space is formed in the impeller so that the air is sucked in and thrown out thereafter. Since the impeller keeps rotating, the air is continuously sucked in and thrown out and this ensures the continuous flow of the air. Compared to the reciprocating compressor, the advantages of the centrifugal compressor include its compact structure, small size, light weight and continuous and uniform exhaust. Besides, the centrifugal compressor does not require an intermediate tank. As a result, the centrifugal compressor generates less vibration and requires fewer consumables.
The blades of the inlet guide vane device near the impeller and the air let can rotate for modifying the flow of the fluid, or even for closing the channel. However, today's structure for the rotation of the blades is too complicated, thereby resulting in poor efficiency. Consequently, it is important to improve the rotation structure of the blades, in order to control the flow of the fluid effectively.